How to prevent personal belongings such as luggage or suitcases from theft during travel is a problem drawing people's universal concerns. To solve this problem, there are luggage anti-theft devices in the prior art as shown in FIG. 6. A motion sensor is enclosed in a rigid housing, and theft behavior or abnormal movement is deduced according to output information of the motion sensor. Take a common luggage as an example. Once a user turns on the luggage anti-theft device and connects it physically with the luggage or place it in the luggage, the luggage anti-theft device may constantly detect movement of the luggage. If the luggage is abnormally moved beyond a predetermined distance, an alarm built inside the luggage anti-theft device will send out an alarm to inform the user. At present, many motion sensors of this type employ an acceleration sensor, it works by the principles of a piezoelectric effect, and acceleration upon movement may make a piezoelectric transistor deform equivalent to an effect of a received pressure. The acceleration may be converted into voltage output so long as relationship between the generated voltage and the applied acceleration is calculated. The acceleration sensor may obtain a speed through primary integration, and obtain a displacement through secondary integration. In view of the working principles of the motion sensor, when the luggage is moved abnormally on the ground, this type of anti-theft device may generally work effectively. However, when a user gets onboard a transport vehicle such as airplane, the alarm might be falsely triggered due to turbulence during the flight. It is easy to imagine that the alarm is likely to be triggered falsely and much inconvenience is caused when other transport vehicles generate larger acceleration as braking abruptly or bumping on the road surface. More importantly, in the case of “pick-pockets”, current luggage anti-theft devices cannot recognize that an individual article inside the luggage is stolen while the luggage is not moved as a whole.
Furthermore, a common theft technique happens on the plane is that a thief waits for an opportunity to open the suitcase carried by the passenger and steals valuable articles therein, returns the suitcase afterwards instead of taking away the whole suitcase. According to various cases in the past, thieves rely on the assumption that other travelers do not know that the luggage does not belong to them. When the victim realizes that items have been stolen, it is usually too late as there is no easy way to determine who the thieves are. In other words, in this case, only the articles in the suitcase rather than the whole suitcase are stolen. As for a thief, stealing articles from the suitcase is of lower risk of being caught than stealing the whole suitcase. Although theft is prevented by employing a conventional manner of adding a lock, carry-on luggage such as backpacks usually do not have a suitable position for adding a lock. Furthermore, a thief can very easily cut the suitcase to steal articles from inside. Therefore, people especially need an anti-theft device which is capable of effectively preventing articles in carry-on luggage or suitcase from theft.
In addition, on occasions such as home and office, people usually do not want other persons to randomly take away and use their personal articles placed in unlocked wardrobe or drawers without authorization. However, in face, even though these personal articles are used randomly by other persons, it is very difficult for the owner to find it out. Similarly, people especially need a technology capable of preventing personal articles placed in the unlocked wardrobe or drawer from being used by other persons randomly or recording the random use behavior without authorization.